Shunt-based interventions: Why, how, and when to place a shunt.

The broad categories of surgical fetal therapy can be separated into either open surgical techniques or minimally invasive endoscopic/ultrasound-guided techniques that require only puncture of the uterus with single or multiple small ports. Benefits of fetoscopic or ultrasound-guided fetal intervention include decreased uterine irritability, decreased incidence of preterm labor, and avoidance of risks associated with hysterotomy and commitment to cesarean delivery for future pregnancies. Fetal abnormalities potentially amenable to ultrasound-guided drainage techniques include thoracic fluid-filled lesions and lower urinary tract obstruction.